柔性配电网的安全域模型

Security Region Model for Flexible Distribution Network

提出了柔性配电网(flexible distribution network,FDN)的安全域模型,并与传统配电网(traditional distribution network,TDN)对比分析。首先,介绍了FDN的概念与特点。其次,分析了FDN正常运行N-0和N-1下的安全约束。再次,提出了FDN的安全域模型以及安全边界方程。最后,通过单联络与多联络电缆网算例验证了本文方法的正确性,对FDN和TDN的N-0域、N-1域以及供电能力进行了对比研究。对比发现:1)FDN能扩大N-0/N-1域,提高正常运行情况下带负载的能力与N-1安全性;2)FDN达到不计及N-1和计及N-1下的最大供电能力工作点相比TDN多很多,使其在实际中更容易实现;3)FDN节点负荷能突破馈线容量限制,具有更大的局部带大负荷能力。同时,通过二维视图观察总结FDN安全域的形状特点及形成机理,并揭示其与柔性闭环特征的内在联系,最终从安全和高效角度分析得出多联络更适合发挥FDN作用的结论。

The paper proposes a model of security region for flexible distribution network（FDN） and compares it with traditional distribution networks（TDN）.Firstly,the paper presents FDN concept and features.Secondly,security constraints of normal operation N-0 and N-1 are discussed.Then,FDN security region is modeled and region boundary formulations are proposed.Finally,N-0/N-1 security region and supply capability of FDN and TDN are studied with singleand multi-connection cases.Results show correctness of the proposed method,and find out that：1） FDN can expand N-0/N-1 security region,improving load supply capability under normal operation and N-1 security;2） Number of operating points at total supply capability of FDN is more than TDN,making it easier to achieve in practice;3） Load power of a FDN node can exceed feeder capacity limit,leading to a better capability of local load supply.Meanwhile,from two-dimensional security region view,shape characteristics and formation of FDN security region are summarized,and internal relations between the factors and flexible closed-loop characteristics are revealed.From the view of security and efficiency,multi-connection is more suitable for FDN.